Koolasuchus emerging from water


Koolasuchus was a giant amphibian of the Cretaceous Period that measured an astounding five metres from nose to tail and weighed half a tonne. Its wide, heavy head made up about a sixth of the total body length. Eyes on the top of the head allowed Koolasuchus to be an effective aquatic ambush predator, that struck at small mammals and dinosaurs coming to the water's edge for a drink. It was a survivor from an earlier time, the majority of other temnospondyl amphibians having perished at the end of the Triassic. Since it lived in the polar regions, Koolasuchus probably hibernated to get through the winter, as many modern salamanders do today.

Scientific name: Koolasuchus

Rank: Genus

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Koolasuchus size

A graphic illustration comparing the size of Koolasuchus with an American crocodile and humans: the crocodile is the longest, t

A comparison of Koolasuchus' size (4m long) to a human and the 5m long American crocodile.


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Additional data source: Animal Diversity Web

When they lived

Discover the other animals and plants that lived during the following geological time periods.

Cretaceous period Cretaceous period
The Cretaceous ended with the most famous mass extinction in history - the one that killed the dinosaurs. Prior to that, it was a warm period with no ice caps at the poles.


  1. Life
  2. Animals
  3. Vertebrates
  4. Amphibians
  5. Temnospondyli
  6. Chigutisauridae
  7. Koolasuchus